Add plots

[rneswold]

The app still doesn't support the row type that plots parameters.

Plots rows should provide the following features:

• Time series (i.e. numeric devices vs. time)
• Logic plots (i.e. boolean devices vs. time)
• X-Y plots (i.e. numeric devices vs. numeric device)
• Polar plots (i.e. numeric devices vs. numeric device returning degrees)